My ideas for saving fuel is for city traffic engineers to program traffic lights to have the green light start blinking ten seconds before it turns to yellow. This now allows fifteen seconds notice you either are or not going to make the green light.
How will this save fuel? Simply by allowing drivers advanced notice to ease off the gas sooner.
I believe that this is a matter of programming and not a major costly endeavor. No special equipment change out needed.
Now, how do we get this idea in front of the people who can make it happen?